Conversion of Farmall Cub from 6 to 12 volt

I am using a Delco Remy 11SI 110 amp 12 volt one wire Alternator with 3.0 ohm internal resistance and internal cooling fans. I am replacing the ampere meter with a voltage meter which I believe to be more sensitive to charge and discharge movement and also beneficial in assisting diagnosing other electrical circuit problems. I am replacing and rewiring the ignition switch with a key ignition switch and the coil with a 12 volt coil and replacing light bulbs from 6 to 12 volts. My question is, I have been led to believe it is necessary to ground the above identified Alternator with a common ground source as used by the battery negative ground cable. Is this true and, if so, where would you recommend the Alternator be grounded and how would you recommend that wiring be accomplished? I am keeping all the replaced parts as they are in relatively excellent condition and some parts I had already once replaced. Thanks in advance for all anticipated courtesies. Farmall Fran

You alternator will be grounded through the mounting brackets... NO extra grounding is required.

In HD, high Amp applications sometimes a ground wire to the alternator is used, definitely NOT necessary with the Amp draw of a Cub.

There have been some discussions on here in the past about 1 wire alternators on tractors- most require you to rev the engine to initially excite the alternator, and some tractors won't rev high enough to do it. The 10SI (3 wire) might be more suitable.

Provided the alternator mounting bolts are to good clean (NOT all paint or rust or grease covered) frame or engine members, the alternator frame to tractors frame should suffice for the Ground. If there happens to be a FRAME GROUND screw on the alternators case and it makes you feel better, use a stranded copper wire from there to the tractor frame or one of the mount bolts.

I take it the alternator is NEGATIVE Ground so be sure and connect the battery that way.

If its a coil distributor ignition the coils + receives switched voltage from the IGN switch while the - wires to the distributor.

If you remove the ammeter remember it used to make up the series connection from the gennys output to the ungrounded battery post, the alternators output has to get to the battery to charge it WELL DUH......The ammeters load (NOT to battery) terminal may have supplied hot battery voltage to loads like lights and ignition so insure those loads are now fed voltage.

I personally prefer an ammeter to actually show net charging current into a battery or net discharging current out of a battery, but if you like a voltmeter thats obviously your choice. Hey if a body had BOTH you could really be vigilant

John T

When 12 volt batteries first came out magazines like Popular Mechanics and Popular Science ran articles about what a mistake this was ,how cars were breaking down and how a same size six volt was a much better battery than a 12 volt jamming 6 cells where there was three. I do notice a six volt battery to have some deep cranking power.A bit off topic but it got me thinking when I was reading an old magazine about this.

When you are "led to believe" something consider the source, and what they are actually asking you to do.

In this case, a ground wire can't possibly hurt. The alternator *SHOULD* be grounded plenty well enough with just the mounting bolts. A little "belt-and-suspenders" treatment won't hurt a thing.

You almost certainly can get away without it, but adding one is a small expense, and not very difficult to do.